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Q & A: Red Giants and Beyond

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Most recent answer: 10/22/2007
Q:
How long does a star remain in the Red Giant stage and what occurs to the star during the Red Giant stage?
- Abbie
Pioneer High School, Ann Arbor Michigan US
A:
When a star becomes a red giant, most of the hydrogen fuel in the core of the star has been used. The helium shell around the core contracts and heats up. The temperature eventually gets high enough that the hydrogen shell outside the helium starts to undergo fusion. That makes the outside of the star expand enormously. As it expands, it cools off very quickly. The star spends about 100 million years as a red giant. That is actually very short compared to the 10 billion years a star like the sun spends in it's normal stages.


Adam

(published on 10/22/2007)

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